Electric apparatus



June .2 1, 1932. G. w. CARPENTER ELECTRIC APPARATUS Filed Oct. 30, 1925Patented June 21, 1932 PATENT OFFICE GLENN W. CARPENTER, OF SCHENECTADY,NEW' YORK, ASSIGNOR TO GENERAL ELEC- TRIO OOHPANY. A CORPORATION OF NEWYORK ELECTRIC APPARATUS Application med, October 30, 1925. Serial No.65,862.

My invention relates to electric apparatus comprising a plurality ofthermiomc electron dischar e devices, and has for its principal object te provision of circuit arrangements for connecting the cathodes of thedevices to a source of heating current either in parallel or series withone another and for excluding the anode current of each device from thecathode circuits of the remaining devices when the cathodes areconnected in series.

It is frequently desirable that the cathodes of thermionic dischargedevices comprised in an electric apparatus, such as a radio receivingoutfit, be adopted to be supplied with heating current either from a lowvoltage battery or from a high voltage source of rectiiied current. Thecathodes may be connected in parallel to the low voltage source and inseries to the high voltage source. If the cathodes are connected inseries to the high voltage source, diflicult is encountered due to thefact that the ano e currents of some of the devices. In accordance withmy invention this diiiculty is avoided by connecting each V21's cathodein parallel with a shunt having a resistance value dependent on themagnitude of the anode current that tends to be transmitted through thecathode.

My invention will be better understood from the following descri tionwhen considered in connection with t e accompanying drawing and itsscope will be pointed out in the appended claims.

Referring to the drawing, Fig. 1 shows a receiving apparatus providedwith a graded resistance element which is located outside the apparatuscasing and is adapted to complete a series connection between thecathodes 0f the devices comprised within the casing; Fig. 2 shows anintegral bus structure adapted to replace the resistance element forconnecting the cathodes in parallel with one another; Fig. 3 is adiagrammatic representation of the circuits of the apparatus; and Fig. 4illustrates certain details of the circuit connections.

Fig. 1 shows a receiving apparatus com= prisin a casing 1 provided withterminals 2 to taps 22 to 30 of a resistance element 31, or to taps 32to 50 of an integral bus structure 5l. Suitable means, suoli as screwsthreaded into the terminals 2 to 20, are provided for maintainingcontact between the different sets of taps and the terminals. The upperends of the taps of the resistance element and bus structure are slottedso as to be readily slid under the heads of the screws and clamped intocontact with the terminals mounted on the casing. The connections madeby resistance element 31 and bus structure 51 respectively will bereadily understood from Fig. 3.

Fig. 3 diagrammatically shows a plurality of thermionic electrondischarge devices 52 to 59 which are mounted above the casing 1 insockets in the top of the casing and are provided respectively withcathodes 60 to 67 rids 68 to 75, and anodes 76 to 83. It will geobserved that the terminals 2 and 4 to 19 are connected to the grid andcathode leads of the devices 52 to 59, that leads 84 and 85 connectedrespectively to terminals 2O and 3 are provided for transmitting heatingcurrent to the cathodes `60 to 67, and that the anode currents of thedevices 52 to 59 may be transmitted through lead 85 and suitable leads91, 92 and 93 connected to the anodes of the various devices, throughthe circuit arrangement illustrated by Fig. 4.

This arrangement comprises conductors 94 and 95 adapted to be connectedto a suitable source for transmitting rectilied alternating current tothe valves 52 to 59 through smoothing means, shown as reactors 96 andcondensers 97, and through a resistor 98 which is grounded at one endthrough a condenser 99 and is partly shunted by a glow tube 100 formaintainin a constant voltage drop across the shuntedg portion of theresistor. The resistor 98 is rovided with terminals 84', 85', 91', 92',an 93 which are connected respectively to the terminals indicated inFig. 3 by the corresponding unprimed reference numerals.

Assuming the bus structure 51 to be connected to the terminals 2 to 20,the cathodes 60 to 67 are connected to the bus conductors 86 and 87 inparallel, the bus conductors 86 and 87 are connected to the leads 84 and85 respectively, the grids 68 to 72 and 74 are' connected to grid busconductor 88 and the cathode 61 is connected to the cathode 62 through abus conductor 89 and an adjustable resistor 90 that is provided forpurposes of volume control. With these connections, current is suppliedto the parallel connected cathodes through leads 84 and 85 and the voltaes of grids 68 to 72 and 74 are dependent on e potential of grid bus 88.The grid 73 1s connected to the cathode for the reason that device 57 isutilized as a detector. The potential of grid 75 may be derived from aseparate source. Under the conditions described, there is no tendencyfor the anode current of one device to be transmitted through the otherdevices because the cathodes are connected in parallel with one another.

With the resistance element connected to the terminals 2 to 20, thecathodes of the various devices are connected to leads 84 and 85 inseries with one another and are shunted by di'erent sections of theresistance element 31. If the resistance element were omitted, the anodecurrent of each device would be transmitted through all the succeedingdevices. Thus with the source of current supply connected as shown, thesum of all the anode currents would be transmitted through cathode 67.This diiiiculty is avoided by connecting dierent sections of theresistance element 31 in shunt with the cathodes of the various devices,the resistances of the various sections beinr graded to maintain thepotential dro s o all the filaments at the same value. ith thesesections properly determined by the contact points of terminals 22 to 30of the resistance element 31, the apparatus may be readily ada ted toutilize a low volta e battery or a hig voltage source of recti edcurrent for heating the cathodes of the various devices. It should benoted that the resistance element 31 serves both to maintain the cathodecurrent at a constant value throughout the heating circuit and todetermine the bias of grids 68 to 72 and 74 which are connected to thecorresponding cathodes through different sections of the resistanceelement. In case the cathode of one tube should burn out the cathodes ofthe other tubes would remain lighted by current flowing through theshunt and the defective tube can be readily located.

The embodiment of the invention illustrated and described herein hasbeen selected for the purpose of clearly setting forth the principlesinvolved. It will be apparent, however, that the invention issusceptible of being modied to meet the diierent conditions encounteredin its use and I therefore aim to cover by the appended claims allmodifications within the true spirit and scope of my 6B invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is:

1. The combination of a plurality of electron discharge devices eachprovided with a cathode and an anode and with a rid arranged to controlthe current transmltted between said cathode and anode, a receptacleprovided with sockets for said devices and with a plurality of terminals-mounted on the outside of said receptacle, circuit connections enclosedwithin said receptacle and connected between said terminals and saidsockets, and an impedance device provided with taps arranged to engagesaid terminals for connecting the cathodes of said electron dischargedevices in series and causing a bias potential to be applied to saidgrids.

2. The combination of a plurality of electron discharge devices eachprovided with a cathode and an anode and with a grid arranged to controlthe current transmitted between said cathbde and anode, a receptacleprovided with sockets for said devices and with a plurality of terminalsmounted on the outside of said receptacle, circuit connections enclosedwithin said receptacle and connected between said terminals and saidsockets, and a resistor provided with taps arranged to enga e saidterminals and connect the cathodes o said devices in series with oneanother.

3. The combination of a plurality of electron 'discharge devices eachprovided with a cathode and an anode and with a grid arranged to controlthe current transmitted between said cathode and anode, a receptacleprovided with sockets for said devices and with a plurality of terminalsmounted on the outside o said rece tacle, circuit connections enclosedwithin sai receptacle and connected between said terminals and saidsockets, and an im edance device provided with taps arrange to cooperatewith said terminals for connecting the cathodes of said devices inseries with one another and to complete circuits whereby the heatingcurrents of said anodes are maintained equal irrespective of the anodecurrents of said electron discharge devices.

4. The combination of a plurality of electron discharge devices eachprovided with a cathode and an anode and with agrid arranged to controlthe current transmitted between said cathode and anode, a receptacleprovided with sockets for said devices and with a plurality of terminalsmounted on the outside of said receptacle, circuit connections enclosedwithin said receptacle and connected between said terminals and saidsockets, an im edance device provided with taps arrange to cooperatewith said terminals for connecting the cathodes of said devices inseries with one another, and a bus structure provided with taps arrangedto coo erate with said terminals to connect the cat odes of saidelectron discharge devices in parallel with one another.

5. The combination of a plurality of electron discharge devices eachprovided with a cathode and an anode and with a grid arranged to controlthe current transmitted between said cathode and anode, a receptacleprovided with sockets for said devices and with a plurality of terminalsmounted on the outside of said rece tacle, circuit connections enclosedwithin sai receptacle and connected between said terminals and saidsockets, and a bus element provided with taps arranged to cooperate withsaid terminals to connect the cathodes of said electron dischargedevices in parallel with one another.

In witness whereof I have hereunto set my hand this 29th da of october1925.

GL N W. oAizPENTER.

CERTIFICATE 0F CORRECTION.

Patent No. 1,864,482. June 2l, 1932.

GLENN W. CARPENTER.

lt is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction as follows: Page l,line 14, for "adopted" read adapted, and line 23, after "devices" insertthe words are transmitted through the cathode circuits' of otherdevices; and that tbe said Letters Patent should be read with thesecorrections therein that the saine-may conform to the record of the casein the Patent Office.

Signed and sealed this 27th day of September, A. D. 1932.

M. J. Moore,

(Seal) Acting Comissloner of Patents.

of said electron discharge devices in parallel with one another.

5. The combination of a plurality of electron discharge devices eachprovided with a cathode and an anode and with a grid arranged to controlthe current transmitted between said cathode and anode, a receptacleprovided with sockets for said devices and with a plurality of terminalsmounted on the outside of said rece tacle, circuit connections enclosedwithin sai receptacle and connected between said terminals and saidsockets, and a bus element provided with taps arranged to cooperate withsaid terminals to connect the cathodes of said electron dischargedevices in parallel with one another.

In witness whereof I have hereunto set my hand this 29th da of october1925.

GL N W. oAizPENTER.

CERTIFICATE 0F CORRECTION.

Patent No. 1,864,482. June 2l, 1932.

GLENN W. CARPENTER.

lt is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction as follows: Page l,line 14, for "adopted" read adapted, and line 23, after "devices" insertthe words are transmitted through the cathode circuits' of otherdevices; and that tbe said Letters Patent should be read with thesecorrections therein that the saine-may conform to the record of the casein the Patent Office.

Signed and sealed this 27th day of September, A. D. 1932.

M. J. Moore,

(Seal) Acting Comissloner of Patents.

